The invention relates to a system for cleaning a gas such as air by removing contaminants in the form of particles and liquid particles and, more particularly, the invention relates to a system which includes an assembly of vortex cleaners disposed side by side in the path of the gas and a barrier filter of the depth type which is located downstream of the vortex cleaner assembly. As the gas passes through the vortex cleaners, each cleaner imparts a rotational flow to the gas to separate and remove the larger particles and liquid droplets. Thereafter, the fine particles and the finely divided liquid particles are deposited in the filter. A system of this general type is disclosed in Sun et al U.S. Pat. No. 4,158,449.
In prior systems of this type, the filter plugs at an abnormally high rate with the result that the pressure drop across the filter increases at a substantially higher than normal rate as the loading of contaminant particles in the filter increases. The potential dirt capacity of the filter, therefore, is not attained.